Monitor power consumption of your electronic devices remotely via a mobile Blynk app. This simple device is based on a D1 Mini micro-controller. Connect your power source via the DC input channel and your device via the DC output. The monitoring device is powered via a micro usb. There is an on/off switch to control power.

Step 1: Parts and Schematic

You will need the following parts:

D1 Mini
https://www.banggood.com/D1-Mini-NodeMcu-Lua-WIFI-ESP8266-Development-Board-p-1044858.html?p=KF2715792233201409DJ&custlinkid=89596
INA219 Power Monitor Sensor
https://www.banggood.com/custlink/K3m3ttRLec

2 x DC Jack
https://www.banggood.com/10pcs-5_5-x-2_1mm-DC-Powe...

Mini Rocker Switch
https://www.banggood.com/custlink/KG3KPHyoj

Simply connect the parts as shown in the schematic, solder the switch in place after assembly within the 3D printable housing (see next section).

Note: To allow use of the sleep mode you will also need to solder a connection between the RST and D0 pins of the D1 mini.

Step 2: 3D Print the Parts

Download and print the two parts. Assemble the electronics within the parts and secure in place using a glue gun.

Step 3: Blynk App

Install the Blynk app from the Google Play or Apple App Store.

Use the QR code to download the custom Blynk app. Make note of your Blynk authentication token (under the app settings), you will need to copy this to your sketch in the next section.

Step 4: Configure and Upload the Sketch

In order to upload the sketch you will first need to install the esp8266 board and two libraries, if you haven't done so already.

To install the esp8266, add the following URL to the Additional Boards Manager URLs in the Preferences window of the Arduino IDE.

http://arduino.esp8266.com/stable/package_esp8266com_index.json

Now within Boards Manager, install the esp8266 board.

Using the library manager, install the Adafruit INA219 and Blynk libraries.

Amend the sketch for your own WiFi SSID, password and Blynk authentication token. Attach the D1 mini using a micro-usb and upload the sketch.

Power_Montor_v1_0_Blank.ino
Download

Step 5: Connect Your Supply/device and Monitor

Now simply connect your power supply/battery to the input jack and your device to the output jack. Connect the D1 mini using a micro-usb cable for power and flick the switch to power your device.

Load the Blynk app and you can now monitor the device's voltage and power supply. Adjust the slider to enable the status LED to signal when the battery/source voltage drops below the specified value.You can also enable sleep mode to save power i.e when powering the monitor from a battery.

Step 6: Ideas for Further Development

You could expand on this project by incorporating a relay to allow remote power control. Power via battery or the DC source itself might also be useful. See my website http://www.cabuu.com for more ideas and similar projects.